src/json.c: Simplified json :discard for maintanabilty
src/json.c: Simplified json :discard for maintanabilty

jddurand/c-marpaESLIF,jddurand/c-marpaESLIF,jddurand/c-marpaESLIF,jddurand/c-marpaESLIF,jddurand/c-marpaESLIF